[sdiy] bizarre pic-midi issues

[Karl Ekdahl]

So i've gotten somewhere but it's getting weirder - i started using the computer directly to output note on/offs and every 2nd note is fine while every second note adds 0x66 ONLY to the second byte. super ultra weirdness.

so if i send
0x90 0x34 0x40 (key 33 ON velocity 40)
the pic gets
0x90 0x34 0x40 (key 33 ON velocity 40)

if i send
0x80 0x34 0x64 (key 33 OFF velocity 40)
i get
0x80 0x34 0x64 (key 33 OFF velocity 40)

BUT if i send
0x90 0x33 0x64 (key 33 ON velocity 40)
i get
0x90 0x99 0x64 (key 99 ON velocity 40)

any odd-number second byte get screwed up.

thoughts?

Karl


--- Den fre 2010-04-16 skrev cheater cheater <cheater00 at gmail.com>:

> Från: cheater cheater <cheater00 at gmail.com>
> Ämne: Re: [sdiy] bizarre pic-midi issues
> Till: "Karl Ekdahl" <elektrodwarf at yahoo.se>
> Kopia: Synth-diy at dropmix.xs4all.nl
> Datum: fredag 16 april 2010 22:44
> Karl,
> I remember the MIDIBOX project has had problems with the
> onboard UART
> in some of the pics. It had a bug which made it useless for
> MIDI. They
> had to use an external UART, try checking ucapps.de and the
> forums for
> more info. I remember the bug persisted in revisions for a
> few long
> years, and is one of the small things why the project was
> slowly but
> surely ported to C so that they don't have to deal with a
> limiting
> platform.
> 
> Cheers,
> D.
> 
> On Fri, Apr 16, 2010 at 18:37, Karl Ekdahl <elektrodwarf at yahoo.se>
> wrote:
> > Hi list, i've stumbled upon some very bizarre PIC MIDI
> issues. I'm able to send MIDI just fine, but when i try to
> receive it i half the time get junk and half the time get
> good data. Usually (for me), the issue seems to be to find
> the right speed settings, but as the transmission works fine
> that can't be it. The hardware seems rock solid so i really
> don't understand what's going on... any hints or thoughts
> would be awesome! Oh yeah it seems to work "okay" if i use
> the PIC ONLY to process MIDI, but if i try and do anything
> else in the same loop i only get garbage - that's on a PIC
> running at 12MHZ - can't be right. But transmission still
> works..
> >
> > Thanks
> >
> > karl
> >
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >
>